Sewing-machine tension device



(No Model.)

G. W. BURGESS.

SEWING MACHINE TENSION DEVIGE.

No. 254,794. Patented Mar. 14,1882.

UNITED STATES PATENT Orrrcn.

GEORGE W. BURGESS, OF BOSTON, MASSACHUSETTS.

SEWING-MACHINE TENSION DEVICE.

SPECIFICATION forming part of Letters Patent No. 254,794, dated March 14, 1882.

Application'filed July 5, 1881.

To all whom it may concern:

Beit known that I, GEORGE 'W. BURGESS, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Sewing-Machine Thread-Tension Devices, of which the following is a specification.

The object of my invention is to provide an automatic thread-tension device which shall control the tension equally the same with a fine or coarse thread employed in the needle or shuttle, or with either one fine or coarse, or, however much the two threads may vary as r to size or quality, the tension shall remain the same as desired upon each thread at all times; and it consists in the construction, combination, and arrangement of two journaled disks orwheels, the inner faces or surfaces of which are adapted to be revolved at a slight angle or inclination with each other by the passage .of the thread between the same at or near their peripheries, the angle of inclination being automatically adjusted by the size of thread acting between such faces of the disks or wheels, which are held together at-the desired pressure by the influence of a suitable spring, as hereinafter more fully described and set forth.

Figure 1 represents a perspective view of my invention applied to the latch of a shuttle, the latch being thrown out of position. Fig. 2 represents a top plan view of the same with the latch in position for use. Fig. 3 represents a horizontal section of the same. Fig. 4. represents an elevation of the same. Fig. 5 is a'horizontal section of tension device enlarged.

A represents a sewing-machine shuttle provided with a latch, B, pivoted to the heel of the shuttle, and'provided with a thread-eye, G, as heretofore, the thread E leading from the bobbin H through said eye 0, and thence between the rotary wheels or disks F and L, and thence around the bearing or carrier near the periphery of said wheels, and thence back through the said eye 0 again, as shown. The wheel F is adapted to be revolved upon the journal or pin P, secured to the said latch B and projecting within the shuttle A, said pin (No model.)

being flattened upon one side and provided with a wedge-shaped piece, R, which is pro vided with a hole corresponding with the form of the pin P, so as to prevent it from turning thereon, the point of the wedge-piece B being placed toward the point of the shuttle. Then the disk or wheel L is placed upon the said journal or pin 1?, upon which it fits loosely, and is retained thereon by the flat steel spring T, adjustably secured to the shuttle-latch B, as heretofore, its free end being provided with a hole, which passes over the exposed end of the said journal or pin P and rests upon the said disk or wheel L, opposite the point end of the I Wedge-piece R, and thereby inclines the said .disk or wheel L at that side, so as to permit the thread to enter between the said wheels F and L at the opposite side, and thus cause it to impin ge upon the thread E as it is drawn through between the said wheels F and L,thereby rotating the same, but not in the same plane, which plane varies according to the size of the thread, which is.retai'ned near the peripheries of the said wheels F and L by a series of pins, S, which project at right angles from the face of one of said disks, to which they aresecured, and pass through corresponding holes formed in the opposite disk; or one of the said disks may be provided with a circular projecting rib or flaiige and the opposite disk provided with a corresponding groove, whereby the same result may be accomplished; or any other suitable means may beemployed to serve the purpose contemplated.

It will be seen and understood that this tension device controls the lower or shuttle thread, and that an exact duplicate tension device may be arranged to control the upper or needle thread and connected with the needle arm, bar, or any other part of the machine where tension devices are usually connected, or at any point desired between the upper spool and the needle adapted to serve the purposes contemplated. Therefore I have omitted to illustrate the same, as my invention need not be further described, as its construction and operation are substantially the same in either case, shuttle-machines, or those using an upper and under thread, known as double-threaded machines, requiring two tension devices, and l means of the wedge R and spring T, whereby 1o single thread machines requiring only one the tension of the thread passing between the tension device, as heretofore. same near their peripheries may be automati- Having thus described my invention, what cally regulated, substantially in the manner I claim isdescribed, as and for the purposes set forth. Asewing-maehine rotarythread-tension con- GEORGE W. BURGESS.

sistin g of the wheels or disks F' and L, adapted Witnesses:

to be rotated upon the journal or pin P at a SYLVENUS WALKER,

slight angle of inclination witheach other by W. R. MARBLE. 

